Problem: What do the following two equations represent? $-x+2y = 4$ $-x+2y = -2$
Putting the first equation in $y = mx + b$ form gives: $-x+2y = 4$ $2y = x+4$ $y = \dfrac{1}{2}x + 2$ Putting the second equation in $y = mx + b$ form gives: $-x+2y = -2$ $2y = x-2$ $y = \dfrac{1}{2}x - 1$ The slopes are equal, and the y-intercepts are different, so the lines are parallel.